Coloring material for lubricating oils



Patented Aug. 22, 1950 Edward Paul, Zehner, Houston, and Olen Doyle Hunn, Pasadena, Tex., assignors to Sinclair Refining' Compa-ny', New York, N; Y., a corporation of Maine- NoDrawing Application April 16, 19417, SeriaLNo. 741,950

@Claims. (Cl. 196-142) We have discovered a new and. cheap source of dye for use in impartin a commercially desirable fluorescence to" lubricating oils. Our invention embraces a process for manufacturing the dye and lubricating oil compositions containing the same.

Although the color of an oil is no indication of its;- lubricating value, the trade shows a deflnite preference for oils which reflect green when held to the light. Accordingly, it is? the practice where the oil does not naturally show a greenish bloom or fluorescence to add to. it some sub.- stance. which will impart the characteristic. The materials conventionally used for this. purpose contribute considerably to the cost of the finished oil and as a consequence much effort has been expended toward finding cheap substitutes.

We have now discovered that a suitable dye can be readilyprepared from a heavy gas oil constituting a by-product of a catalytic crackmg process.

The process to which we refer is identified in the oil industry as the Thermofor or TCC process and is distinguished in that it involves the use of a bed of catalyst particles which is caused to move downwardly through a reaction chamber against a stream of vaporized oil constituting the charge stock. In the operation of the system, the spent catalyst is conveyed from the bottom of the reactor to a kiln where it is regenerated by burning it in air, while the cracked products, withdrawn from the top of the reactor, are passed to a fractionator which is ordinarily operated to yield, in addition to a gasoline fraction and a heavy gas oil bottom product, a fraction suitable for recycling to the reactor.

It is the heavy gas oil bottom product, boiling within the range 500 F. to 800 E, which We employ in the preparation of the dye. In accordance with out invention, we first reduce this product, after filtering or settling when necessary to remove suspended catalyst, by distillation, ordinarily with the aid of open steam in order to lessen the heat requirements, until the volume of the residue does not substantially exceed 10% of the volume of the material subjected to reduction. Most suitably, the reduction or distillation is continued until the material is reduced to a volume approximating about of the volume of the original material.

Following the reduction, the residue is blown with air or other oxygen-containing gas to obtain the dye which itself is brownish-green in color. The air blowing is an essential step. serving' to stabilize the color of the dye. Normally this operation isconducted at a temperature of about 180 F. over a period of about one hour, but a lower temperature may be used if the period is extended or the period may be shortened by using a higher temperature.

Before utilizing the dye we customarily reduce its viscosity in order to render it more easily handled by adding to it about 10% of light oil. Filtration of the dye or blend is not usually necessary.

The dyemay beaddedto lubricating oils in any amount which imparts th desired cast without adversely affecting the quality of the oil. However, we have found that from 0.25 to 1.0% of the dye on the weight of the oil ordinarily su-flices'. The dye appears to be fully effective in the preseneeof addends, such as anti-oxidants, viscosity index i-mprovers', pour depressors, etc. employed in the preparation of compounded oils.

The detailed practice of our invention is illus trated by the following examples:

Example I tests on the dye were as follows:

Gravity 7.3 Flash 435 Vis./210 62 Pour 110 Concarbon per cent 7.25 Sulphur do 0.30

Example II The dye produced as above was admixed with a lubricating oil having a Saybolt viscosity of about 300 secs. at 100 F. to reduce the viscosity. The blend containing dye and 10% oil was then added, in such amounts as to give a dye concentration on an oil-free basis of about 0.5%, to five lubricating oil stocks each showing a reddish bloom. In each case the bloom changed to the desired shade of green.

The laboratory tests on the oils to which the dye was added are given in the table below, which also shows the color reading before and after addition of the dye.

Color Gr "t Fl sh V's 100 V's /2l0 Pour c0101- F 8X1 y a l l Addltmn of Dye 22. 3 355 306 47 B -10 2+ 4%+ 21. 9 385 50s 51 B -10 2+ 43 21. 7 405 754 62 -10 2, 42 21.4 425 1, 225 77 3+ 9 21. 7 460 2, 031 100 3% e The color measurements were made with an ASTM union eolorimeter designated DI 55-45T.

We claim:

1. Method of preparing a dye adapted to impart a greenish fluorescence to lubricating oils not naturally possessing a greenish cast which comprises distilling a heavy gas oil boiling within the range 500 F.800 F. to a residue having a volume not substantially exceeding 10% of the volume of the oil distilled and thereafter blowing the residue with an oxygen-containing gas, said heavy gas oil constituting the bottom product of a fractionator into which are introduced cracked. products from a catalytic cracking reactorutilizing a bed of solid catalyst particles which is caused to move through the reactor against vaporized oil to be cracked.

2. Process according to claim 1 where the volume of the residue approximates 5% of the volume of the oil distilled, where the reduction is accomplished with the aid of steam, and Where the blowing following the reduction is with air at a temperature of the order of 180 F.

3. A lubricating oil to which agreenish bloom has been imparted by the addition thereto of from about 0.25 to about 1.0% on the weight of the oil of a dye produced by distilling a heavy gas oil boiling within the range 500 F.-800 F. to a residue having a volume not substantially exceeding 10% of the volume of the oil distilled and thereafter blowing the residue with an oxygen-containing gas, said heavy gas oil constituting the bottom product of a fractionator into which are introduced cracked products from a catalytic cracking reactor utilizing a bed of'solid catalyst particles which is caused to move through the reactor against vaporized oil to be cracked.

A lubricating oil to which a greenish bloom has been imparted by the addition thereto of from about 0.25 to about 1.0% on the weight of the oil of a dye produced by distilling a heavy gas oil boiling within the range 500 F.-800 F. in the presence Of steam to a residue having a volume not substantially exceeding 5% of the volume of the oil distilled and thereafter blowing the residue with air at a temperature of the order of 180 F., said heavy gas oil constituting the bottom product of a fractionator into which are introduced cracked products from a catalyltic cracking reactor utilizing a bed of solid catalyst particles which is caused to move through the reactor against'vaporized oil to be cracked.

EDWARD PAUL ZEHNER. OLEN DOYLE HUNN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,566,000 Hanna et a] Dec. 15, 1925 1,974,777 Keeling Sept. 25, 1934 1,974,778 Lang Sept, 25, 1934 1,988,753 Shaffer et a1 Jan. 22, 1935 2,047,780 Henny July 14, 1936 2,051,255 Harger Aug. 18, 1936 FOREIGN PATENTS Number Country Date 586,005 France Dec. 20, 1924 

1. METHOD OF PREPARING A DYE ADAPTED TO IMPART A GREENISH FLUORESCENCE TO LUBRICATING OILS NOT NATURALLY POSSESSING A GREENISH CAST WHICH COMPRISES DISTILLING A HEAVY GAS OIL BOILING WITHIN THE RANGE 500*F.-800*F. TO A RESIDUE HAVING A VOLUME NOT SUBSTANTIALLY EXCEEDING 10% OF THE VOLUME OF THE OIL DISTILLED AND THEREAFTER BLOWING THE RESIDUE WITH AN OXYGEN-CONTAINING GAS, SAID HEAVY GAS OIL CONSTITUTING THE BOTTOM PRODUCT OF A FRACTIONATOR INTO WHICH ARE INTRODUCED CRACKEDPRODUCTS FROM A CATALYTIC CRACKING REACTOR UTILIZING A BED OF SOLID CATALYST PARTICLES WHICH IS CAUSED TO MOVE THROUGH THE REACTOR AGAINST VAPORIZED OIL TO BE CRACKED. 